Timing Questions for TTC a girl.

We are going to be swaying for a girl and I have a question about timing. When we conceived our daughter, I know that we only DTD one time the entire month. We had just moved to Georgia and were working opposite shifts so we didn't have much time for BDing. I wasn't charting or using anything to predict ovulation, so I have no idea when she was actually conceived. I knew my LMP date but had no idea when I ovulated compared to when we DTD. With our son, I was charting (temps, OPKs, OVwatch, etc.) We were BDing pretty much every other day up until O then we did it everyday for three days straight. We were NOT trying to sway in anyway just plain TTC. SO....Abstaining seemed to work for us to get a girl, where more frequent BDing got us a boy. So originally my timing plan was to abstain and go for O+12, but now I'm wondering if I would be ok to just do an abstain with cut-off instead. Since I don't know the timing of when our daughter was conceived, I am having a hard time deciding which to do! Any suggestions???